Chemical That Can Irritate Lungs Found in Flavored E-Cigarettes

FRIDAY, Jan. 29, 2016 (HealthDay News) -- People using flavored e-cigarettes, particularly ones that taste like cherry, are likely inhaling a chemical that can irritate their airways, a new study suggests.

"It might be the case that if the user of an electronic cigarette experiences some side effects, like coughing, it might be attributed to the flavorings," since the chemical benzaldehyde was detected in 108 of the 145 flavored cigarettes tested in the study, said senior author Maciej Goniewicz. He is an assistant professor of oncology at Roswell Park Cancer Institute in Buffalo, N.Y.

Benzaldehyde is a widely used flavoring agent found in foods as well as medicines, such as cough syrup, Goniewicz said. It can taste like cherries or almonds.

"It's safe when we eat it, or when we apply it to our skin, but inhalation is a completely different mode of exposure," Goniewicz explained.

Benzaldehyde can irritate the airways when inhaled, and vapor from the chemical also can irritate the eyes, he said.

However, the researchers also noted that the estimated daily inhaled dose of benzaldehyde from even cherry flavored e-cigarettes was more than 1,000 times lower than the maximum workplace exposure level set by federal regulators.

And the Smoke-Free Alternatives Trade Association, an e-cigarette industry group, said in a statement that these findings prove e-cigs are a better alternative to traditional tobacco cigarettes.

"Let's not lose sight that vaping presents substantially less risk than combustion cigarettes, which expose smokers to over 7,000 chemicals including more than 60 known or suspected carcinogens," the statement said. "This research shows that even with cherry e-cigs, it would take three years of vaping to reach the 8-hour work shift permissible occupational exposure limit."

But Dr. Norman Edelman, senior scientific advisor for the American Lung Association, said the study really shows the need for proper regulation of e-cigarettes.

"To me, it's another piece of evidence that we don't know what's in those things," Edelman said. "It's terribly important that the U.S. Food and Drug Administration use its power to regulate them. The first thing they can do is find out what is in them."

E-cigarettes work by heating a liquid solution to its boiling point, creating a vapor that users inhale. The liquid often contains nicotine, and sometimes also contains other flavorings.

Goniewicz and his colleagues measured the benzaldehyde contained in 30 puffs taken from 145 different e-cigarette liquids. In this study, they used an automatic smoke inhaler to measure the chemicals in the e-cigarettes.

The findings are published online Jan. 28 in the journal Thorax.

The researchers found benzaldehyde in three out of four e-liquid vapors tested. But the highest levels were in cherry-flavored products -- likely a sign that those liquids use the cherry-tasting chemical more heavily, Goniewicz said.

Goniewicz said "vapers" should know about this and switch if a flavored e-cigarette starts causing them to cough.

"If someone is using electronic cigarettes right now and experiences some of these side effects, this study suggests that they should try a different flavoring that might be less irritating to the users," he said.

But Goniewicz stopped short of calling on e-cigarette users to quit the devices, particularly if they are likely to take up tobacco cigarettes as an alternative.

"The evidence is really strong that the electronic cigarettes are less harmful than tobacco cigarettes," he said.

But Edelman noted that there's no solid scientific evidence showing that e-cigarettes help smokers quit, and that the devices instead help them maintain their nicotine addiction.

"People shouldn't vape," Edelman said. "If they're trying to stop smoking, there are FDA-approved nicotine-replacement products. If e-cigs are effective at smoking cessation -- and there's no evidence of that yet -- then they're no more effective than FDA-approved products already on the market."

Edelman added that flavorings are a way to entice young people to try e-cigarettes, which is one reason why the FDA has banned the use of flavorings other than menthol in tobacco cigarettes.

"There is a way to deal with this, and that's for the FDA to issue regulations," he said. "They said they were going to a year ago, and they haven't done it yet."